Hello,

Thank you @AllyCat and @Werk_AG for your comments.

I have a 0.5 Watt Round Polycrystalline waterproof Solar Panel (2.5v, 250ma, 11.2cm diameter) which I would like to use to measure W/m2 in my home.

I have already some other sensors in my station (temp, humidity, etc.) and decided to include also the solar radiation measurement.

For voltage and current reading I have the INA219 (current shunt and power monitor with I2C interface), which I thought of using for this measurement but seems that the reading the voltage (with a accurate calc of the Rsh) seems the way to go...

Thank you @AllyCat and @Werk_AG for your comments.

I have a 0.5 Watt Round Polycrystalline waterproof Solar Panel (2.5v, 250ma, 11.2cm diameter) which I would like to use to measure W/m2 in my home.

I have already some other sensors in my station (temp, humidity, etc.) and decided to include also the solar radiation measurement.

For voltage and current reading I have the INA219 (current shunt and power monitor with I2C interface), which I thought of using for this measurement but seems that the reading the voltage (with a accurate calc of the Rsh) seems the way to go...